Heidelberg Castle’s Haunted Wine Barrel. The world's largest wine cask, the Heidelberg Tun was built in 1751 from the trunks of 130 oak trees and has a capacity of 58,124 gallons. It is 28 feet deep by 23 feet high. The balustraded platform on top was built as a dance floor. Login Login 0 repins 0 comments 0 likes